Recommended Posts

I was reading the manual for the kiln I have. It says to keep the lid open until 1000 degrees. WIth my old kiln (small 1960's paragon) I kept the lid proper with a 1" furniture for the first hour. Is it necessary to prop the lid open on an electric programmable kiln?

Share this post

Link to post

Share on other sites

The reason to keep the lid propped, is control the rise in temperature, as well as to let moisture out. If you have a programmable kiln, and have dry wares, there's really no reason to prop the lid, except to expedite the end of the cooling process. I just usually pull a couple plugs, to vent the moisture, and allow quicker cooling, at the beginning and end of the firing respectively.

I will also note, that in my first classroom, the lid was propped with a bit of a broken post. i continued to do so, with my firings, and it slowly damaged the lid. it was putting stress on the brick, where the screws were drilled in for the metal banding.

Share this post

Link to post

Share on other sites

With our Cress e-23 we leave the top peephole unpugged with the lid closed. I don't even prop the lid open for pre-heats, as the steam and moisture seem to have no problem escaping with the lid closed.

The only exception to this is when we're doing a gilding firing where we leave the lid propped-open until around 500 F to let the volatile and toxic fumes escape, per the instructions on gilding material.

When we previously used a very much older Cress kiln of the same size, but with 24 amps instead of 36, someone in our studio got it into their head that "all dampers have to be open for an oxidation firing". Of course he was reading about gas kilns, but to him this meant both peephole plugs had to be open. With both peepholes open the Cone 6 firing timed-out and never reached anywhere close to Cone 6 as the heat loss from both peepholes being open was greater than the heat the kiln could generate.

Share this post

Link to post

Share on other sites

Computerized kilns should not have the lid propped. If it's vented with a downdraft vent, you should also keep the peep holes plugged. If you leave the computerized kiln propped open it can cause an error code. I've seen it happen. One of the reasons they used to recommend the lid be propped was to slow down the rate of limb when the kiln was first started, to prevent steam explosions. This was especially true in old kiln that just had on-off switches, not 4 position or infinite switches. But even with those, 'Low' could get hot enough to cause problems. With the computer, the rate of climb is precisely controlled so it's not an issue.

Share this post

Link to post

Share on other sites

Ok- Now I have another question. (i hope I am not annoying everyone with all my questions)

When I am setting the kiln with the option to sound an alarm for a temperature, I would like to have it beep when the kiln is at 200 degrees (safe to open) - would it sound when it reached 200 as it was heating or would it sound when it cools to 200? Is it loud and obnoxious or is it a little beep?

Share this post

Link to post

Share on other sites

Probably just never changed it when the digital controllers came out. Even with manual kilns I personally have never propped the lid except when doing a preheat with wet pots. If your pots are thin and dry it isn't necessary.

Share this post

Link to post

Share on other sites

I stopped propping my lid a while ago after I saw another thread here, but I usually keep both peeps out until red heat to allow better circulation as I have no vent (small test kiln). Is this a waste of energy for me to do this?